Gear reduction assemblies are often used to facilitate to the use of a less powerful input force or prime mover to perform tasks on high loads. Gear reduction assemblies may also reduce output speed based on the input of a prime mover having an undesirably high output speed.
An example of an application where a gear reduction assembly may be desirable is a winch. For example, winches are often used to deploy or retract a line, such as cable, against a heavy load. Such winches may be hand-operated or motor-driven. Winches may be used when transporting solid and/or liquid cargo via barges along bodies of water. With an increase in a desire to transport cargo more efficiently and with less undesirable emissions, the use of barges to transport cargo has become increasingly attractive. For example, recent studies indicate that transport of cargo by barge is more than 25% more efficient than transport by rail and more than three times as efficient as transport by truck. In addition, transport of cargo by barge results in significantly less undesirable emissions than transport by rail and truck.
In order to increase the efficiency of transport of cargo via barges, a number of barges may be grouped together in a barge “train” or “tow” by cables and pushed or pulled by a single or several boats. For example, as many as forty barges may be held together in a group of five rows by eight rows.
In such barge “trains” or “tows,” it may be desirable to adjust the tension and/or length of the cables holding the barges together to facilitate control of the barges during the release or addition of barges with respect to the group, or during navigation of a waterway. A common device for facilitating such adjustments is a hand-operated hoist sometimes referred to as a “come-a-long.” However, hand-operated hoists, while very portable, suffer from a number of possible drawbacks, such as physically-demanding operation and a tendency to become misplaced.
An alternative to hand-operated hoists is winches, which may be either hand-operated or motor-driven. However, conventional winches may suffer from a number of possible drawbacks. For example, many winches have a drum around which the line or cable is wrapped. However, the diameter of the drum may be relatively small in order to permit use of a relatively small motor or render it easier to reel up the line by hand. This may lead to a number of possible drawbacks related to the line being tightly wrapped around the relatively small drum, such as, for example, creating kinks or deformations in the line, which may have memory due to the large diameter of the line. This may promote problems with the use of such a winch under certain circumstances.
Moreover, some conventional winches rely on a locking ratchet gear to hold a load resulting from the tightening of a cable by the winch. Although a ratchet gear may be effective for holding a load, a ratchet gear is inherently either fully engaged or fully disengaged, and thus, when a load held by a ratchet gear is released, the operator of the winch has no control of the rate of release of the load. Such an uncontrolled release of a large load is potentially dangerous to the operator.
Thus, it may be desirable to provide a gear reduction assembly that provides a relatively dramatic gear reduction in a relatively compact manner. Further, it may be desirable to provide a winch that has a relatively large diameter drum that may be driven with relatively less effort via hand and/or relatively less power via a motor. It may also be desirable to provide a winch that facilitates a controlled release of a large load, for example, at a controlled rate.